Open block family duration limited by temperature variation

Patent metadata

Field	Value
Publication number	US-12423013-B2
Application number	US-202318490040-A
Country	US
Kind code	B2
Filing date	Oct 19, 2023
Priority date	Aug 19, 2020
Publication date	Sep 23, 2025
Grant date	Sep 23, 2025

Abstract

A system includes a memory device and a processing device, operatively coupled to the memory device. In some embodiments, the processing device accesses a matrix of threshold voltage offset bins, where a first dimension of the matrix is temperature and a second dimension of the matrix is a temporal voltage shift (TVS) amount. The processing device measures a temperature value based on a reference temperature value for a block family. The processing device measures a TVS value of a voltage level within one or more memory cell of the block family. The processing device retrieves, from the matrix, a threshold voltage offset bin based on the reference temperature value and the TVS value and reads data from any page of the block family via application of a threshold voltage offset, specified by the threshold voltage offset bin, to a base read level voltage.

First claim

What is claimed is:

1. A system comprising:
a memory device; and
a processing device, operatively coupled to the memory device, the processing device to perform operations, comprising:
accessing a matrix of threshold voltage offset bins, where a first dimension of the matrix is temperature and a second dimension of the matrix is a temporal voltage shift (TVS) amount;
measuring a temperature value based on a reference temperature value for a block family of the memory device;
measuring a TVS value of a voltage level within one or more memory cells of the block family;
retrieving, from the matrix, a threshold voltage offset bin based on the reference temperature value and the TVS value; and
reading data from any page of the block family via application of a threshold voltage offset, specified by the threshold voltage offset bin, to a base read level voltage.

2. The system of claim 1 , wherein the operations further comprise recording a temperature value based on the reference temperature value for the block family.

3. The system of claim 1 , wherein the operations further comprise:
initializing the block family associated with the memory device; and
responsive to programming a page residing on the memory device, associating the page with the block family.

4. The system of claim 3 , wherein the reference temperature value associated with the block family comprises at least one of:
a temperature value measured for memory cells programmed while the block family is open; or
an average of measured temperature values for the block family while the block family is open.

5. The system of claim 3 , wherein the operations further comprise:
measuring an opening temperature of the memory device at initialization of the block family;
determining a temperature metric value by integrating, over time, an absolute temperature difference between the opening temperature and an immediate temperature of the memory device; and
closing the block family in response to the temperature metric value being greater than or equal to a specified threshold temperature value that is based on a threshold temperature function of an absolute temperature value, wherein the absolute temperature function varies with a reference temperature value associated with the block family.

6. The system of claim 5 , further comprising a plurality of temperature sensors, wherein each temperature sensor of the plurality of temperature sensors is coupled to a respective die of a plurality of dice of the memory device, wherein at least one of the temperature sensors is to measure the opening temperature and the immediate temperature.

7. The system of claim 6 , wherein the temperature metric value is associated with a single die of the memory device, and wherein the operations further comprise:
determining an average of the temperature metric value for the plurality of dice; and
wherein closing the block family is performed in response to the average of the temperature metric value being greater than or equal to the specified threshold temperature value.

8. The system of claim 6 , wherein the temperature metric value is associated with a single die of the memory device, and wherein the operations further comprise:
determining an aggregated temperature metric value over the plurality of dice;
in response to determining that a first temperature metric value for a first die of the plurality of dice is greater than or equal to a maximum threshold temperature value, excluding the first temperature metric value from the aggregated temperature metric value; and
wherein closing the block family is in response to the aggregated temperature metric value being greater than or equal to the specified threshold temperature value.

9. A method comprising:
measuring, by a processing device, a temperature value based on a reference temperature value for a block family of a memory device;
retrieving, from a temperature bin offset vector, a first threshold voltage offset bin value based on the temperature value;
measuring a temporal voltage shift (TVS) value of a voltage level within one or more memory cells of the block family;
retrieving, from a TVS bin offset vector, a second threshold voltage offset bin value based on the TVS value;
determining a threshold voltage offset bin by summing the first threshold voltage offset bin value and the second threshold voltage offset bin value; and
reading, by the processing device, data from a page of the block family via application of a threshold voltage offset, specified by the threshold voltage offset bin, to a base read level voltage.

10. The method of claim 9 , further comprising recording a temperature value based on the reference temperature value for the block family.

11. The method of claim 9 , further comprising:
initializing the block family associated with the memory device; and
responsive to programming a page residing on the memory device, associating the page with the block family.

12. The method of claim 11 , wherein the reference temperature value associated with the block family comprises at least one of:
a temperature value measured for memory cells programmed while the block family is open; or
an average of measured temperature values for the block family while the block family is open.

13. The method of claim 11 , further comprising:
measuring an opening temperature of the memory device at initialization of the block family;
determining a temperature metric value by integrating, over time, an absolute temperature difference between the opening temperature and an immediate temperature of the memory device; and
closing the block family in response to the temperature metric value being greater than or equal to a specified threshold temperature value that is based on a threshold temperature function of an absolute temperature value, wherein the absolute temperature function varies with reference temperature value associated with the block family.

14. The method of claim 13 , wherein measuring the opening temperature comprises measuring a temperature of one of a thermocouple or a controller that is coupled to the memory device.

15. The method of claim 13 , wherein the temperature metric value is associated with a single die of the memory device, the method further comprising:
determining an average of the temperature metric value for a plurality of dice of the memory device; and
wherein closing the block family is performed in response to the average of the temperature metric value being greater than or equal to the specified threshold temperature value.

16. The method of claim 13 , wherein the temperature metric value is associated with a single die of the memory device, the method further comprising:
determining an aggregated temperature metric value over a plurality of dice of the memory device;
in response to determining that a first temperature metric value for a first die of the plurality of dice is greater than or equal to a maximum threshold temperature value, excluding the first temperature metric value from the aggregated temperature metric value; and
wherein closing the block family is in response to the aggregated temperature metric value being greater than or equal to the specified threshold temperature value.

17. A method comprising:
accessing a matrix of threshold voltage offset bins for a memory device, where a first dimension of the matrix is temperature and a second dimension of the matrix is a temporal voltage shift (TVS) amount;
measuring a temperature value based on a reference temperature value for a block family of

Assignees

• Micron Technology Inc

Inventors

• Sheperek Michael
• Koudele Larry J
• Liikanen Bruce A
• Kientz Steven Michael

Classifications

• G06F3/0679

  Non-volatile semiconductor memory device, e.g. flash memory, one time programmable memory [OTP] · CPC title

• G01K1/026

  arrangements for monitoring a plurality of temperatures, e.g. by multiplexing · CPC title

• G01K3/04

  in respect of time · CPC title

• G01K3/005

  Circuits arrangements for indicating a predetermined temperature (fire detection G08B17/00) · CPC title

• G01K7/02

  using thermoelectric elements, e.g. thermocouples · CPC title